Spider-Man: Across The Spider-Verse - How to build a pipeline for variable rate animation

Variable rate animation, or stepped animation, is the process of holding a frame of an animation performance between two or more frames, as opposed to keeping a consistent motion of performance through each and every frame.

The art direction on Spider-Verse aimed to bring the look of the project closer to a comic book and hand drawn traditional animation. Using the variable rate animation method helped the project get closer to the desired style with some key differences.

Using the variable rate animation technique contradicts the hard technical requirements for simulation tasks in modern CG animation, which needs evaluation on a constant per-frame basis for accurate results. This technical contradiction was only partially solved for Into the Spider-Verse, causing a lot of friction, communication overload and workflow difficulty between animation and downstream simulation departments. For the sequel, Across the Spider-Verse, we created a new dedicated end-to-end non-destructive pipeline layer that could fully solve this issue